Maybe you should talk to Arthur, he is about to build some controlllers. His thread was in the Equipment section this past week. His price is way under the imports.
Dew Buster all the way here (how did you fry one !?)
Very well made, custom options available - good for dobs esp.
The Kendricks is a total pain with low battery warnings etc (again big issues at the top of a dob UTA)... thousand oaks is ok, but the dew buster is more sophisticated with the temp sensors (optic and ambient) calculating the dew point and setting an offset.
Long story short - never once had issues with dew. Very stingy on battery usage though - so no excess heat either.
I've got no idea! I'm sure someone with a little electronics nous could look at it and tell me what's wrong with it. I'm a complete Gumby with these things and wouldn't know where to start looking.
As Glenn mentioned below now making my own fro imported parts. Each channel is run with a separate pulse width modulator (max 120w/ch, although this is never reached in astronomy scopes unless your a hero and want to melt your scope)
Each output is individually controlled and the output is dependent on the resistance of the strap you are using ( I tend to make mine out of nichrome wire).
Frying?? If it happens, which is unlikely, you just replace the fried channel, not the entire unit... Keep the fuse low also for protection
I would be surprised if anyone needed more than 20-25w max for dew heater, but that is open to discussion
Remember the idea is not to radically heat the thing, it's just to keep it a few degrees above dew point
